Yang was selected as an astronaut candidate in 1998 and has trained for space flight since then.[2] He was chosen from the final pool of 13 candidates to fly on China's first manned space mission. A former fighter pilot in the Aviation Military Unit of the PLA, he held the rank of Lieutenant Colonel at the time of his mission.[2] He was promoted to full Colonel on October 20, 2003.[5] According to the Youth Daily, the decision had been made in advance of his spaceflight, but Yang was not made aware of it.[5]

He was launched into space aboard his Shenzhou 5 spacecraft atop a Long March 2F rocket from Jiuquan Satellite Launch Center at 09:00 CST (01:00 UTC) on October 15, 2003.[6] Prior to his launch almost nothing was made public about the Chinese astronaut candidates; his selection for the Shenzhou 5 launch was only leaked to the media one day before the launch.[1]

Yang Liwei has reported the apparition of abnormal vibrations 120 seconds after launch, he described as "very uncomfortable". As a consequence, corrective measures were swiftly taken to the design of the following CZ-2F carrier rocket for the Shenzhou-6.[7]

Yang punctuated his journey with regular updates on his condition—variations of "I feel good", the last coming as the capsule floated to the ground after re-entry.[3][8] He spoke to his wife as the Shenzhou 5 started its eighth circuit around the Earth, assuring her from space: "I feel very good, don't worry".[3][8] He ate specially designed packets of shredded pork with garlic, Kung Pao chicken and eight treasure rice, along with Chinese herbal tea.[5] In the middle of the journey, state television broadcast footage of Yáng waving a small flag of the People's Republic of China and that of the United Nations inside his capsule.[5][8]

State media said Yang's capsule was supplied with a gun, a knife and tent in case he landed in the wrong place.[8]

Yang's craft landed in the grasslands of the Chinese region of Inner Mongolia at around 06:30 CST on October 16, 2003 (22:00 UTC), having completed 14 orbits and travelled more than 600,000 km.[8] Yang left the capsule about 15 minutes after landing, and was congratulated by PremierWen Jiabao.[8] But the astronaut's bleeding lips seen in the official images broadcast sparked rumours of a hard landing confirmed by accounts of personnel present at the landing site.[9]

Yang visited Hong Kong on October 31, 2003, holding talks and sharing his experiences during a six-day stay in the territory.[11] The visit coincided with an exhibition that featured his reentry capsule, spacesuit and leftover food from his 21 hour mission. On November 5, he travelled to Macau.[11]

In a move similar to those taken by the Soviet Union and the United States (with national space flight heroes Yuri Gagarin and John Glenn, respectively), an official decision to no longer assign him to spaceflight missions was made (note: Glenn subsequently flew a second space flight on October 29, 1998, on Space Shuttle Discovery's STS-95). Yang was promoted to Major General on July 22, 2008.[14]